Drainage System Page:
French Drains - A Centuries Old Solution to Your Current Water Problem
Excess water in your yard can be a pain. Having your home or garage flood every time you get a heavy rain can be even worse. Inadequate yard draining can keep you from your chores, from enjoying your lawn, or it can even wear away your home's foundation, causing structural damage.
A surprisingly simple but incredibly effective solution for
problem exterior drainage issues is a French Drain. French Drains weren’t
invented in France,
the name comes from a 19th century farmer from Concord
In a nutshell what a French Drain does is intercept and drain the water via an underground pipe to a safe drainage location. Essentially it is a ditch with a pipe laid in it that is covered with rock. The French Drain collects and redirects surface and ground water to prevent it from penetrating or damaging building foundations, basements, garages, etc.. The French drain technique may also be used to distribute water, such as that which flows from the outlet of a typical septic tank sewage treatment system. French drains can also used behind retaining walls to relieve ground water pressure. It is a time-tested technique that can be put into place to solve any number of issues that pertain to water damage as a result of poor drainage.
Outlined below are the basic techniques that we use when building a French Drain system. A French Drain of the type that we build is a gravel filled trench with a buried 4" pipe inside of it. While some French Drains don’t have a pipe at all, simply a trench filled with #57 gravel, we build ours in a way that is best suited to issues common with Flordia yards and their water problems, and that means using a pipe!
A common difference between our technique and others is we
build trenches that are at least eight inches wide, and usually up to twenty
four inches in depth, as opposed to the more commonly used six inch trench. We
do so because a wider French drain will last longer, the capacity to collect
and disperse water is better when larger, and it is easier to dig and grade a
wide French drain, especially when a deep one is required. Let’s look at each
of these areas individually…
A wider French drain will last longer because the primary cause of failure in a French Drain is silting up of the spaces between the #57 gravel by clay and soil – and a wider system simply has more gravel in it and takes longer to clog up. French drains only fail when the gravel becomes full of sand or when the drainage pipe becomes full of plant roots and the bigger the trench, the less potential there is for it to get clogged up! . To further prevent clogging we cover the trench in landscape cloth and wrap the pipes in drain sleeve fabric. Seemingly simple concepts to be sure but many contractors don’t take these steps when building a French Drain system. The capacity to collect and disperse water is better in a wide French drain. Think about how much more water can flow through a 12 inch channel as compared to a 6 inch channel. With a French Drain you want to allow as much water to soak into the soil in dryer parts of the yard, and a length of French drain that is 12 inches wide has twice the drainage area as a 6 inch wide trench, pretty simple right? But surprisingly most contractors dig a 6 inch trench, giving you half the bank for your buck! There are also small dry wells that can be added to the bottom of the French drain trench as needed and it is much easier to dig these in a wider trench.
So why do some contractors build smaller drains? It’s simple really, digging a French Drain trench is HARD WORK! If you have ever tried to plant a bush or a tree in your yard you can get an idea of the amount of work it takes to dig a 12” wide by 24" deep by 50’ long trench. It’s not just digging a trench however, part of the art of building a perfect French Drain is grading the trench so the water is collected and flows as effectively as possible. It seems simple and it is really, to let gravity and water pressure do the work, but it takes a lot of experience to set the French Drain up so those two forces are working to move the water where it needs to go when it needs to get there.
Cost: Typically we charge around $7 to $13 per linear ft., this varies from site to site. These Prices include all materials and labor. For more information please feel free to email us at: scentedcleaning@aol.com
